Wheel alignment instrument



- May 30, 1950 R. A. LEACH WHEEL ALIGNMENT INSTRUMENT 2 Sheets-Sheet 1 Filed May 22, 1947 y 1950 R. A. LEACH ASWAW WHEEL ALIGNMENT INSTRUMENT Filed May 22, 1947 2 Sheets-Sheet 2 Patented May 3%, 1950 UNITED ATENT OFFICE 2,509,466 WHEEL ALIGNMENT INSTRUMENT Raymund ALLeacli, Everett, Pa. Application May 22, 1947,.seria1No. 749,815

The present invention aims to provide a wheel alignment gauge, which may be manipulated with great facility, is accurate; and may be employed on all t pes of modern cars and trucks to assist in the proper alignment of the wheels and simultaneously center the steering;

More particularly the present invention provides an apparatus which may be inserted between the front wheels of an automobile ortruck, be retainedin position between the wheels while the desired adjustment or the wheels to prbper alignment is being made, the gauge providing an indicationof the degree of misalignment at the beginning of the operation andofthe progress of the correction to show Whenthe wheels are in proper alignment.

For this purpose the present gauge" comprises a pair of telescoping tubeswith ani'riteri'or spring so that the ends of the gauge are ssed and spring held in position-between the wheels during the adjustment operation.

Another object of the invention is to facilitate the manipulation of the gauge in the space between the wheels. For this purpose the present invention comprises a latch whichholds-the gauge ina shortened condition against the compressed springthe latch acting both to latch and unlatch the gauge without direct manipulation.

Another phase of the present invention resides in providing thegauge with spherical contact elements which fit intoand engage the bottom of the annular groove of the felly band of the wheel rim which provides an accurate seat for the ends of the gauge.

As another object of the invention; and to facilitate the accurate adjustment of the tbe-i11 of the front wheels the gauge is provided with a spirit level at each end so that when in use the gauge may be maintained in a horizontal position.

Other objects and advantages of the present invention will be apparent to personsfskilledin the art from the following specification and the accompanying drawings, which illustrate one embodiment of the present invention; it being understood that variations therefrom falling with in the scope of the appended claims will suggest themselves to those skilled in the art.

In the drawings:

Fig. 1 is a plan view of the gauge,

Fig. 2 is a front view,

Fig. 3 is a sectional view on line 33 ofFig; 2,

Fig. his a perspective view of one end of the Fig. 5- is a fragmentary sectional View of the telescoping tubes,

Fig. 6 is a sectional view on line 6 6 of Fig. 1, an

Fig. '7 is a fragmentary section'on line 'l- -T of Fig.1. W U

While it may be made of any suitable material, the present gauge is largely composed of stock tubular steel material. The gauge comprisesa pair of U-shaped or forked tubular end members H3 carrying the steelcontact balls I l at their ends and a tubular extensible cross member l2 connecting the m'idpoints of the baseportions 13 of the end of forks l0.

The extensible cross member l2 comprises a pairof telescoping'tubes, l4 and I5. The smaller or inner tube !4 has a pin 16, whichis disposed within the elongated slot I in the largertubefli. This serves to limit the relative longitudinal movementof the two tubesand, by reason of the snug fit of the pin it against the Sidesof the slot it, this alsoserves to prevent any relative rotationof the tubes l'4and l5.

A helicalspring I3 is'dispos edwithin the larger tube [5. The spring I8 presses against the end of the smaller tube M. In order to facilitate the manipulation of the gauge and to enhance its accuracy, the cross member 12 is providedwith a latch which can lock and holdfthe gauge in its shortened condition against the pressure oi the'spring l8. The latch consists of meas res 26 held in more orless freely suspended position by theupturned lug Zlat the end of the tube ii. The opriingiir the annulus 20 is oval men-ape andembraces the tube l lloo sely and freely. The annulus'has an inter'ior' notch 22which m e the lug 2i freely. The engagement betweefithe annulus latch z'cend the h1g2 I isfsuoh thatwhile the latch is captured by thelug 2| it has a more or less iree swinging movement. Ata point oppo'sedto the notch 22 andlug' fitthe annulus l i'as an integral weighted portidn 23f The underside or the tube Ithasa n t es, which receives the inner edge of the latch 26 to hold thagaugeinits compressed and shortened conditionagairist the pressure of thespring. M

Referring again" to the end fork'sj lliilo f the gauge, it wil1"loe' seen that the arms 3E0? the U shaped end; members l9 are'bent or curved as shown in F'i'g's. 2 and 4. This remieres-gauge to be disposed well below theundel'structureojf thevehiclewhile the contact balls restfr'e'ely in the rooved brtion 0f th felt? 3! of th wheels.

In" manurectiirewhe some steeTballs I l are selectedfor' sizeto fit into the bottom of the groove of the felly of the wheel so as to ,Ininimite any" fi play of th 'ball in" thgroove. Theball's" l l are brazed onto the open ends of the tubular stock of the arms 30 and the units it are adjusted so that the balls H lie in a horizontal plane as indicated by the spirit level 32 carried by the metallic casing 33 firmly affixed to and rendered integral with the end unit ill by the attachment or securement 34.

Thus the end forks It are rigid, rugged, integral units, which can take the rough treatment of a work shop and their trueness remains preserved.

The mid point of the base portion E3 of each unit It is provided with a flattened area 43, which may be obtained by welding on a fiat element or by flattening or collapsing the tubular stock. The flattened area 40 is received in the bifurcated end 41 of the tube 14 or 85, as the case may be, and is pivotally held there by the bolt or pivot pin 42.

The cross member i2 carries an indicator 43 at each end designed to indicate the alignment of the adjacent wheel. This indicator comprises essentially the base plate 44, which is welded onto the cross member as to the tube Hi as shown in Fig. 6, and the pointer 45 mounted on the plate 44 to have substantial angular movement. The rear end of the pointer 4-5 rests on the stud 46, integral with plate 45, and receives the pivot pin or bolt ll which is held firmly in position by nut 48. The pin 4? provides a pivot bearing for the pointer 45.

The angled end member 45a is secured to plate 44 and has slot 49 which receives the end of the pointer 45. The outer face of the member 44a has scale indicia over and under the slot 49, one set for passenger vehicles and the other for trucks. A cover 59 secured by screws 55 encases the pointer 45.

The two indicators 43 are so mounted, as shown, that the indicator faces are inclined to each other and both can be read from a single position.

The rod 52 transmits motion from the end it! to the pointer 45. The present rod 52 is so constructed and so connected to the end it and pointer that there is no lost motion between the end and the pointer thereby providing an accurate indication of the alignment or toe-in of each wheel. For this purpose the connection between the ends of the rods 52 and the end member ii) at one end and the pointer 45 at the other end are screw threaded connections. These ends of the rod 52 have a minute rotary movement. The screw threaded connections eliminate all lost motion, and the pointers give precise indications of the alignment of the wheels.

In order to facilitate the assembly of the connecting rod 52 with the end it and pointer 45, the rod is made of two parts 53 and 54 which have threads 55 at their ends connected by the interiorly threaded sleeve 56.

The threads 55 are both right hand screw threads and any movement of sleeve 56 will not alter the setting. The opposite end of the rod 53 has a screw threaded pin El which engages internal threads in the walls of the tube it or of an interiorly threaded sleeve 58 which is disposed transversely of the tube it; and welded thereto. Similarly one end of rod 54 has a threaded pin 59 which enters the interior thread in pointer 45. Thus by means of the threaded pins at the end of the connecting rod movement of end Ill is transmitted accurately to the pointer 45.

The outer edge 39 of the flattened portion 40 engages the bottom of the slot on one side or the other at the extreme of the pivotal movement of the fork in relative to the cross member 12. This imposes relatively narrow limits of pivotal movement upon the end forks [8. These limits are such that the free end of the corresponding pointer 45 never engages the ends of the slot 49. In the present apparatus the maximum movement of the end fork ll] is less than five degrees, and the maximum movement of the pointer 45 is about ten degrees.

In order to obtain an accurate indication of the toe-in it is necessary that aside from the movements of the fork l0 and the movement of the pointer 45, which movements are essential, other movements should be reduced to a minimum or entirely eliminated.

In the present construction this end is partly had by limiting the movements of IO and 45 as described in the preceding paragraph. In addition the angles and dimensions established by the connecting rod between the fork Ill and the pointer 45 are such that the rotation of the pins 5'! and 59 are so slight that they cannot be observed by the naked eye. For this purpose the connecting rod is so positioned that the amount of rotation of the pins 5'! and 59 are about equal. For this purpose the pin 5! is located a distance from pivot point 42 which is several fold the distance of pin 59 from pivot point 41. Roughly the relationship of these distances is inversely to the relationship of the angles of maximum travel of the fork and pointer respectively.

Thus by minimizing the rotation of the pins 5'! and 58 and by rendering them about equal and by the employment of screw thread engagements at these points the indicators are accurate and maintain their accuracy throughout the life of the apparatus.

In its normal or inactive condition the gauge is in its compressed condition with the latch 29 in engagement with the notch 24. In this shortened condition the gauge is considerabb ho te than the distance between the wheels of a vehicle. When it is desired to test and adjust the toe-in of the front wheels of an automobile, the operator grips the portions l3 and, after disposing the gauge between the wheels, presses the ends toward each other. This pressure forces the lug 2i and the upper end of the latch 2c to a position overlying the notch 24. The weight 23 then causes the disengagement of the latch from the notch. By the subsequent release of manual pressure the spring It extends the gauge and the contact balls H are caused to be positioned in the felly grooves M. A bit of rocking of the gauge and the grooves are cleared from any obstructions and the ontact balls sit snugly in the grooves. The gauge is permitted to remain in position until the adjustment is completed.

Before any adjustments are made the steering wheel is turned to its center line or to its normal driving position so that the indication given by each indicator will be true for its wheel. After the steering wheel is set, the gauge is set in horizontal position as indicated by the levels 32. The indicators or pointers 4.5 then show the amount of toe-in or toe-out of each wheel.

In cars which have two tie rods, steering centering is required. By means of the present invention this is obtained simultaneously with the adjustment of the toe-in. With the steering wheel set on its center line, each tie rod is turned until its pointer 45 shows the desired toe-in for the wheel. At the completion of this operation the wheels are adjusted and steering is properly centered.

When there is only a sing1e tie rod steering centering is not involved. The wheel alignment may be adjusted at either end of the tie rod or at either wheel. Only one indicator needs to be read after the other has been set and maintained on the zero position. When the adjustment is completed the forks I!) are pressed manually so as to release them from the wheels. When the gauge is removed from under the car the forks ID are again pressed to compress the spring "3 until pin l6 engages the end of the slot ll. By turning the gauge the latch engages the notch 24 upon release of manual pressure, and the pin [6 takes the position slightly spaced from the end of the slot to provide space for the slight compression necessary for the release of the latch.

Thus the present gauge provides a rugged and accurate wheel alignment gauge, which may be employed with great facility and will give accurate and reliable results.

I claim:

1. A wheel alignment gauge comprising a pair of rigid U-shaped end members, a ball rigidly affixed to the free ends of said members for entry into a felly groove, a cross connector between said end members pivotally connected to the midpoint of said end members for limited relative movement therebetween, an indicator carried by said connector adjacent each member, said indicator having a fixed dial and a movable pointer, and a rigid connecting rod between each end member and said pointer, said connecting rod having integral threaded end portions, said end members and pointers each having interiorly threaded portions receiving said threaded end portions.

2. A wheel alignment gauge comprising a pair of rigid U-shaped end members, a ball rigidly affixed to the free ends of said members for entry into a felly groove, a cross connector between said end members pivotally connected to the midpoint of said end members for limited relative movement therebetween, an indicator carried by said connector adjacent each member, said indicator having a fixed dial and a movable pointer, and a rigid connecting rod between each end member and said pointer, said connecting rod having integral threaded end portions, said end members and pointers each having interiorly threaded portions receiving said threaded end portions, the connecting rod being disposed between the end member and pointer to minimize and to equalize rotary movement of its threaded between said parts providing for limited, relative, longitudinal movement of said parts, said interengaging means constraining said parts against relative rotation, a gravity operated latch to hold said parts in compressed condition against the force of said spring, a dial plate rigidly carried by said connector at each end, a pointer pivotally mounted on said plate, and a onnecting rod connected to each pointer and adjacent end memher.

4. A wheel alignment gauge comprising a pair of rigid U- 'haped end members, a ball rigidly affixed to the free ends of said end members for entry into a felly groove, the base of each end member having a flat portion at its midpoint, a cross connector pivotally connected to said fiat portions for limited relative pivotal movement, said cross member comprising a pair of telescoping parts, a helical spring disposed within one of said parts and pressing against the other, interengaging means between said parts providing for relative movement of said parts, a gravity operated latch to hold said parts in compressed condition against the force of aid spring, a plate rigidly carried by said connector at each end, a dial carried by said plate at its front end, said dials being inclined toward each other, a pointer pivotally mounted on said plate, and a rigid connecting rod connected to each pointer and adjacent end member, the connecting rod having integral threaded end portions, said end members and pointers each having interiorly threaded portions receiving said threaded end portions.

5. A wheel alignment gauge comprising a pair of rigid U-shaped end members, each having substantially spherical free ends for entry into a felly groove, a cross connector between said end members pivotally connected to the midpoint of said end members for limited relative movement therebetween, an indicator carried by said connector adjacent each member, said indicator having a fixed dial and a movable pointer, and a rigid connecting rod between each end member and said pointer, said onnecting rod having integral threaded end portions, said end members and pointers each having interiorly threaded portions receiving said threaded end Portions.

RAYMOND A. LEACI-I.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,206,476 Snyder Nov. 28, 1916 1,269,336 Taylor June 11, 1918 1,324,388 Duby Dec. 9, 1919 1,544,980 Hartsock July 7, 1925 1,777,686 Bagge Oct. 7, 1930 1,853,517 Finnerty Apr. 12, 1932 1,894,370 Erickson Jan. 17, 1933 2,164,853 Beckwith July 4, 1939 2,229,352 Thannhauser Jan. 21, 1941 

